System of motor control.



A. CILIURCHWARD.`

SYSTEM OP MOTOR CONTRUL.

APPLICATION FILED APR. 9. 1909.

Patentedsept. 19,1911.\\`

2 SHEETS-SHEET 1.

lgo'oml.

Witnesses: Inventor Alexander Churchward by I @Witty A. OHUROHWARD.

SYSTEM OF MOTOR CONTROL.

APPLICATION FILED APR. 9. 1909.

1,003,431. 1 m5111911 sept. 19,1911.

Fig. Z. Figl 3.

A I 1.( ,4 5\ *f*- illl! l l Hi f @mymuhf A E, 11111 F 1912.4. F v Fig.

A v 4 lillllllll ff lllalmll f? 5! v /r/ \a a/ Fig. 6. Fig. 7.

4 /F ,4, I F j mllilgll r j mmm ff ff a ,f f1 JM/ 5 Fig. 8.

mmm! F" f? 5 .a Fig. 9.

1 F umili/ll F' a\ 5 '111111 Y Fig. IO.v

@1H F mmm F 5 Winessesq imi/@1113er W Afexander Chwarn/Varel,

Amvy.

MM WM/@M with my invention;

4the like.

Unir-'nn strauss rarnna onirica.. i

ALEXANDER CHURCHWARD, OIF NEW YORK, N. Y., ASSIGNOR TO GENERAL .ElllCTlRlCv COMPANY, A CORPORATXON OF NEW' YORK. i

SSTEM OF MOTOR CONTROL.

Looaisi.

To all lwhom it may concern:

Be it known that I, ALEXANDER CHURCH- WARD, a citizen of the United States, residing at New York, in the county of New York, State of New York, have invented certain new and useful Improvements in Systems of Motor-Control, of'which the following is a specifica-tion. A

My invention relates to systems -of control for electric motors andv particularly for motors employed for propelling vehicles and Regenerative employed on motor driven vehicles in which Edison storage batteries are use d. Such storage batteries, when they are called on for heavy rates of discharge, do not recover their electromotive force when the discharge returns to normal. However, any sudden charge of even short duration will tend to freshen them up and increase their eective voltage.

Heretofore, when regenerative braking systems have been used on vehicles ,driven in the braking position and .reverse the cong nections of the series winding.

Other features of novelty which characterize my invention are pointed out in the claims annexed to and forming a part vof this specification. vFor a bet-ter understanding of my invention, however, reference may be had to the following description .taken in connection with the accompanying drawings, in which-d Figure 1 is a diagrammatic .representation of a control system arranged in accordance Figs. 2 to 7, inclusive,

" show motor connections when' the motor is operating as a motor, and Figs. 8, 9 and 10 show the motor connections when the motor is operating as a generator.

Similar reference characters will be used throughout the specification and drawings to denote like parts.

braking systems of motor Acontrol are particularly advantageous when To avoid this rush of current op- Specification of Letters Batent. Patented Sept, 19, 1911, Application filed April 9, '1909. Serial No. 488,841.

Reference being had to Fig. 1, the motor for driving the vehiclehas an armature A, the shunt field winding a, and the seriesfield winding made up of the coils F and F. K

is the motor controller which consists of the row of xed contacts 10 to 21 inclusive, and' the two sets of movable contacts L and M.

R is a resistance to which the fixed contacts 13, 14e, 2O and 21 are connected. S is a reversing switch for reversing the connections of the armature A, and B is a storage battery for supplying power to the system.

When itis desired to start the vehicle in a forward direction, the switch S is thrown to the position for forward movement and the controller is turned so as to bring the fixed contacts into engagement with the contacts L. In the first running'position, the connections are as shown in F1g.2,the motor being connected to the battery as a cumulative compound resistance R. -The movement of the controller 'to the second running position gives the connections shown in Fig. 3, which is similar to Fig. 2, except that the resistance is Vcut out of circuit. A further movement o the controller gives the connections shown in'lig. fi, in whichthe shunt field'has been disconnected, so` that the motor now operates asv a Aseries motor. By leaving the shunt field in circuit for the4 first two running positions, it is possible to get a low running speed in the second position without wasting powerin heating up' the resistance R. Such a speed position is advantae-ous when -it -s desired to run a vehicle in crowded thoroughfares and over railroad crossings. The further movement of the' controller into the fourth position gives the connections shown in Fig. 5, and a higherrunning -speed is obtained because the series field winding is shunted across a portion of the resistance R Still higher speeds may be Obtained in the'fifth and sixth position of controller," the connections for 'which are shown in Figs. 6 and 7, in which the series field 'coils are placed in parallel.` Position six is similar to position ve, except that the .series field coils are shunted across a portion of the resistance R. n case it is desired to reverse the direction of travel of the vehicle, the switch S is thrown into the position for reverse movement and the controller moved lin the same direction asbefore.l

When the vehicle isf descending a grade it motor in series with the total nections are as shown in Fig. 8, in which the motor is connected across the battery as a shunt machine, the series field winding be ing reversed, but short circuited. In the second regenerative position, the connections `for which are shown in Fig. 9, the series field winding is shunted across a portion of the resistance R, so that some of the current generated by the lmotor acting as a dynamo Hows through the series field winding which now has its connections reversed as pointed outabove, so that it assist's vthe shunt field winding to increase the voltage generated by charge.

' it is of the Edison type, as explained above,

the motor, and thus the battery receives a If it is desired to increase the voltage generated lby the motor and thus oits braking effect, the controller is `turned. to the third braking position, the connections for which are shown in F ig. 10 and are similar to the connections shown in Fig. 9, except that the series field is shunted .by the whole -resist-ance R and, consequently, most of the current generated by the mot-or flows through it.

'By using the system of my invention all braking, whether on the level or going down hill, may be done by making the motor run as a generator, and each time the braking actionf occurs a small increment of charge will be added to the battery which, when will freshen up the battery and increase its effective volt-age, so that the motor may be operated at full voltage and, therefore', at full speed until vthe battery charge is eX- hausted.

Although I have described my invention in great detail as embodied in a preferred form, it is, of course, understood that many changes may be made in the arrangement of the field windings and the manner and means for connecting them in order to produce the desired results, and I aim in the appended claims to cover all modifications .within the spirit and scope of my invention. l/Vhat I claim as new and desire to secure by Letters Patent of the United States, is,

l. The method of controlling a motor, which consists in operating it as a series motor, and as a cumulative compound generator when it is overhauled by the load.

2. In a system of motor control, a source of power, amotor having a series and a shunt eld winding,l and means for connecting said motor as a series motor for running and as a cumulative compound gen-l erator when it is overhauled by the load.

3. In a system zit motor control, a Source of power, amotor having a series and a shunt eld winding, and means for connecting said motor as a series motor for running and for connecting the shunt field winding in circuit and for reversing the series field winding when the motor is regenerating.

4.. In a system of motor control, a source 'of power, a motor having a series and a y-i'ng when the motor is regenerating and then increasing the resistance of the shunt so that more current flows through the series eld winding.

G. In a system of motor control, a source of power, a motor having a series and a shunt field winding, a resistance, and means for connecting the shunt. field winding in circuit and for reversingl and shunting the series field winding across said resistance when the motor is regenerating.

7. In a system of motor control, a source of power, a motor having a series and a shunt field winding, a resist-ance, and means for connecting the shunt iield winding in circuit and for reversing and shunting the series field. winding across said resistance when the motor is regenerating and then increasing the amount of said resistance which is placed in shunt with the series field winding.

8. In a system ot motor control, r'a source of power, a motor having a series and a 'shunt eld winding, and a controller for connecting said motor as a series motor for running and as a cumulative compound gen,- erator when it is overhauled by the load.

9. In a system of motor control,a source of power, a motor leaving a series and a shunt field winding, and a controller for connecting said motor as a series motor for running and for connecting the shunt iield winding in circuit and for reversing the series field winding when the motor is regenerating.

10. In a system of motor control,`a source of. power, a motor having a series and a shunt field winding, and a controller for connecting said motor as a series motor for running and for cdnnecting the shunt field winding in circuit and forl reversing and shunting the series 'field 'winding when the motor is regenerating.

l1. In a system of motor control, a source of power, a motor having a series and a shunt field winding,

and for reversing and shunting the fseries field winding whenthe motor is regenerating and then increasing the resistance of the shunt sd that more current flows through the series field Winding.

12. In a system ofmotor control, a source of power, a motor having a series and ashunt lield Winding, a resistance, and a controller for connecting the shunt field Winding in circuit andl for reversing and shunting the series field Winding across said resistance when the motor is regenerating.

13. In a system of motor control, a source of power, a motor having a series and a shunt field Winding, a resistance, and means for connecting the shunt field Winding in circuit and for reversing and shunting the series eld winding across said resistance vwhen the motor is regenerating and then increasing the amount 'of said resistancewhich is placed in shunt With the series field Winding.

lll. In a motor driven vehicle, a storage battery, a driving motor having a series and l; a shunt field Winding, and means for connecting said motor to said battery as a series motor for running and as cumulative cornpound generator when it is overhauled by the loa j l5. In a motor driven vehicle, a storage I and a controller for connecting the shunt field winding 1n circult battery, a driving motor having a series and a shunt field Winding, and means for connecting theshunt field winding in circuit when the motor is regenerating;-

16. In a motor driven vehicle, 'a storage battery, a driving motor having a series and a shunt field Winding, .a resistance7 and means for connecting 'said motor to said battery 'as a series motor for running and for connecting the shunt lield Winding in circuit and reversing the series field Winding'and shunting it acrosssaid resistance When the motor is regenerating.

17. In a motor driven vehicle, astorage battery, a driving motor having a series and,

- *ALEXANDER CHURCHWARD. .Witnesses EDWIN BQII. TOWER, D. ALLEN ROBERTSON.

`Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, 1). C,

.35 and for reversing the series field Winding 'l 

